The present invention relates to the delivery of beneficial agents within the fluid flow of a medical fluid. More specifically, the present invention relates to the control delivery into a fluid flow system of an agent that is dissolved so that it can become part of the fluid flow system.
It is known to parenterally deliver and collect medical fluids. Principally, these fluids are delivered, via an intravenous route or intraperitoneally. Examples of some intravenous fluids include blood and blood fractions, sugar, electrolytes, osmotic solutions, and nutrient preparations. Of course, many beneficial and therapeutic agents are delivered parenterally to avoid the digestive tract and liver. To this end, it is known to add medicaments and other agents to parenteral fluids for their intravenous administration.
Typically, these additional agents are added to a parenteral fluid reservoir by a pharmacist or a nurse. Because the addition of such agents is a labor intensive step, providing the opportunity for mistake and/or error, and further, since many beneficial agents are less stable in solution than in dry form, systems have been developed to facilitate formulation of soluble dry agents with parenteral fluid immediately before use.
Examples of systems to formulate parenteral fluid with soluble dry agents in situ in a formulation chamber associated with a primary delivery device include U.S. Pat. No. 4,552,555. Control delivery of a beneficial agent into a medical fluid can also be achieved through the diffusion of the agent from a non-erodible polymer matrix that contains and serves as a reservoir of the agent. Such systems are described in U.S. Pat. Nos. 3,921,636 and 4,511,353.
It is also known to provide a matrix that contains and/or protects, as necessary, one or more entrapped beneficial agents in a dry, stable state. The matrix, when placed in a flow chamber in a medical fluid administration line, disappears as the agent is delivered into the flowing stream, indicating delivery of the dose.
U.S. patent application Ser. No. 07/345,334, now abandoned entitled: "COMPOSITION AND METHOD FOR ADMINISTRATION OF BENEFICIAL AGENTS BY A CONTROLLED DISSOLUTION", assigned to the assignee of the instant patent application, provides an anhydrous, solid, water-soluble composition for the direct controlled administration of beneficial agents into a flow of medical fluid. The composition includes a matrix that is soluble in the medical fluid and in which the beneficial agent or agents are dispersed. Preferably, the matrix comprises one or more sugars or sugar alcohols in anhydrous solidified melt form. The beneficial agent or agents are distributed in particulate form and in predetermined patterns within the matrix. The beneficial agent can be carried in a conduit through which the medical solution passes. As the solution passes through the beneficial agent, a controlled amount of beneficial agent dissolves into each aliquot of medical solution which passes. The controlled amount per aliquot being substantially uniform for all the aliquots that pass from the first one to the last one.
An example of the use of the controlled administration of the beneficial agent is with respect to blood collected from a donor. As blood is collected from a donor, it passes into a container such as a blood bag which contains an anticoagulant system. Such anticoagulant systems typically include a small amount of liquid solution which is stored in the bag, usually ACD, CPD, CPD-adenine, or the like. In use with the controlled administration of the beneficial agent, the beneficial agent can be an anticoagulant/storage agent through which the blood passes on its way into a container.
U.S patent application Ser. No. 07/121,001, entitled: "AMPULE FOR CONTROLLED ADMINISTRATION OF BENEFICIAL AGENT" now U.S. Pat. No. 5,030,203 discloses a flexible ampule for use with a beneficial agent. The flexible ampule defines a pair of opposed, flexible sides sealingly enclosing a space which contains a mass of beneficial agent which is soluble in aqueous solution. Inlet and outlet ports communicate with the space and exterior of the ampule. Flow promoting means are positioned between the mass of beneficial agent at least one opposed, flexible side, to facilitate the formation of fluid flow paths along the path of the beneficial agent.
It is also known to provide in a set for the intravenous administration or other parenteral administration to a patient of a fluid solution a Y-site. The Y-site functions to provide a fluid flow path from a container to the patient while still allowing, via an injection site, a method for injecting or placing a second fluid or agent within the fluid flow path. To this end, the Y-site typically includes a tube extending from one arm of the Y-site and a tube extending from the bottom of the Y-site. The second arm of the Y-site includes an injection site. Fluid flows from the first arm of the injection site through the bottom of the Y-site into the second tube.
It is also known to provide in a set for parenteral administration a needleless injection site. An example of such a needleless injection site is disclosed in U.S. patent application Ser. No. 07/147,414, abandoned in favor of U.S. patent application Ser. No. 07/539,278, now issued as U.S. Pat. No. 5,188,620. The needleless injection site allows a blunt cannula to enter the injection site allowing the addition of a fluid or agent to the Y-site.